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Back 2019-04-10

How the 303 Became Zipp's Do-It-All Speed Weapon


Flanders, rich in cycling tradition, holds a special place in spurring Zipp's most significant wheel innovations. Photo by Getty Images

Innovation originally intended for the Spring Classics created a wheelset ideal for modern road cycling...

Riding Dirty Kanza? The Zipp 303 is your go-to wheel set. The Tour of Flanders Sportive? Perfect terrain for the 303. The Alps? The 303 is light for climbing and aero for descents or flat sections. Cyclocross? Yep, go with the 303.

You get the picture.

The 303 NSW and Firecrest —with its 45mm rim depth and wide rim/tire bed—is Zipp’s single most popular model. In fact, we offer seven different 303s, more than any other Zipp rim depth. The 303’s rise in popularity speaks to the fundamental changes in road cycling in recent years. Road bikes and road cyclist evolved in significant and sometimes unexpected ways, laying the groundwork for a wide embrace of the 303 as a ready-for-anything wheelset:

  • Carbon wheels became the norm. Once they were durable enough to handle the cobbles of the Spring Classics, riders of all types embraced them. This allowed for gains in aero efficiency at a lighter weight than aluminum wheels.
  • Disc brakes and wider carbon rims opened a new world of wider tires. 23mm is the new narrow. It’s not uncommon for “roadies” to run 28 or 30mm, unthinkable just a few years ago.
  • Road cycling went off pavement. Riders increasingly want bikes that at least give them the option of getting away from it on gravel, dirt, and single track.
  • The definition of racing broadened. The competitive mainstays of criteriums, time trials, road races, and triathlons are now augmented with a whole array of new events and ultra-races. This includes “gravel” and adventure races, gran fondos, and an array of personal challenges.


Roadies are going off road, and the 303 is taking them there with options including the 303 650b. Photo by Jered Gruber

One Wheel, Many Riding Conditions

Around 15 years ago, Zipp engineers set an audacious goal of developing a carbon wheel tough enough to thrive in Spring Classics. Those legendary one-day races include the cobblestones Tour of Flanders and Paris-Roubaix, but also the hills and winds of the Ardennes Classics.

“The Spring Classics is a good model for the way that people ride,” said Michael Hall, Zipp director of advanced development. “In the Spring Classics, it’s a combination of windy conditions, hills, steep hills, lots of varied terrain. “If you look at a Tour de France wheel, you’re going to have a special wheel for the climbing stages, a special wheel for the flat stages. The 303 really provides the ultimate mix. Almost by accident, in developing something for the Spring Classics, you have a have a wheel that really suites today’s riding environment.


The Spring Classics demanded a carbon wheel with durability and versatility over a variety of terrain and road conditions. As it turned out, the 303 provides that ultimate mix for everyday riders, too. Photo by VeloFocus

“Today riders may do a group ride. Then on the weekend an exploratory ride over various terrain. The nature of cycling has kind of shifted, and the 303 has naturally been a good fit for that because it really provides the best for all conditions.”

Each step along the way, Zipp engineers realized the 303 had greater potential to meet the needs of more cyclists as technology and riding habits evolved. Certainly, Zipp remains best known for aerodynamic efficiency with our deep section wheels, and that has not changed. Our deeper rims, including the 404, 808 NSW and Firecrest, 454 and 848 NSW, remain at the core of our product lineup. Yet it’s worth looking at the evolution of the 303 to better understand the changing nature of road cycling.

In 1999, Zipp introduced its now familiar naming convention—the 303, 404, and 808. its roots in triathlon, Zipp was best known for its deeper-section wheels (404 at 58mm, and 808 at 82mm) and disc wheels. The 303, at the start, was an effort to bridge that gap between deep-section “race-day” wheels and everyday aluminum wheels. “These wheelsets are equally at home on the road, on a century ride, climbing the Alps or being pitched into a high-speed criterium corner,” Zipp’s 2000 catalog stated.

In 2005, Zipp unveiled the 44mm deep dimpled 303 wheel with a hybrid-toroidal rim shape. Zipp also introduced the more durable Pave-Cross 303 for cyclocross.


ZIPP 303 Wheelset Clincher - 2007.jpg

The evolution of the 303: Top, the 303 NSW Carbon Clincher Tubeless Disc brake. Bottom, the 2007 303s with aluminum brake track.

For Arenberg and the Ardennes

This era marked the beginning of a bold goal that would define Zipp’s future success—to become the first wheel manufacturer to develop a carbon wheel to be ridden to victory in the Tour of Flanders and Paris-Roubaix. In 2006, Team CSC, riding 303s, became the only pro cycling team to race the Tour of Flanders on carbon wheels.

Failures were frequent. Initial tests of prototype 303 carbon rims on the famed Forest of Arenberg cobblestones of Paris-Roubaix quickly left Zipp engineers with a pile of cracked prototypes.


Fabian Cancella testing 303 prototypes on the cobbles of a then green and peaceful Forest of Arenberg in 2006 with Team CSC. Photo by Getty Images

Back in Indiana, Zipp® engineers went back to work. They mounted stone-sized metal “bumps” onto the spinning drum in the test lab to simulate, as best they could, riding cobbles at race pace. They used a high-speed camera to dissect the cause of pinch flats and cracked rims. The result was the development of Carbon Bridge™ technology, which that reduced impact damage and results in greater tubular wheel stiffness and robustness.

In 2009, Zipp introduced a re-engineered 303 with Carbon Bridge™. At the time, a young engineer named Michael Hall (now Zipp’s advanced development director) talked about the vision behind the new wheel.

His comments hinted at the tech trends that would be all the rage in road cycling by 2019.


Cyclocross required Zipp engineers to make carbon wheels more durable. International cyclocross, with American Kaitlin Keough shown here, was a crucial proving ground for improving the 303 and then introducing the disc-brake version of the 303. Photo by Cyclephotos

In 2009, Hall said: “We actually increased the width of a tire bed to accept larger tires and kind of ballooned it out a little bit to make it more comfortable over the cobbles in Europe. Actually what we found, when we were doing prototype tests and in the wind tunnel, is that it was faster that we first envisioned it. We envisioned it being a cyclocross/pavé lower-speed wheel but more durable. But what we found was we could have both features. We could have a really aero profile and one that was comfortable over the cobbles.”

The wheel was three years in development. Confirmation would come in 2010 when Fabian Cancellara, on two consecutive Sundays, won Tour of Flanders and Paris-Roubaix aboard Zipp 303s. That achievement and the changes that led to it—specifically the aero benefits from a wider profile and durability from the Carbon Bridge—led Zipp engineers to then develop the Firecrest rim shape and Carbon Clincher technology.

Those efforts resulted in the 303’s wider rim – which ultimately served as the inspiration for the Firecrest design.


Fabian Cancellara's win at the 2010 Tour of Flanders marked the first time a carbon wheel was ridden to victory in either Flanders or Paris-Roubaix, which Cancellara would win the next week. This display in the entrance way of Zipp's Indianapolis factory pays tribute to that achievement.

Carbon Clinchers Changed Everything

In 2011, Zipp introduced the 303 Firecrest Carbon Clincher and Tubular, which tested 8 percent faster than the 303 Tubular introduced just two years before. Its max width was 28mm, Zipp’s widest wheel. Carbon Clinchers offered ease of use and greater flexibility to change tires depending on conditions or riding surface.

Professional validation of the wheel came quickly, including Tom Boonen’s Tour of Flanders/Paris-Roubaix double in 2012. Cyclocross also played a crucial role in proving out the versatility of the 303, including Wout van Aert winning the world championship aboard 303s in 2016 and 2017. Meeting the needs of cyclocross racers led to Zipp in 2013 to introduce its first disc-brake wheelset, the 303 Firecrest Disc-brake.

Around this time, road cycling was evolving—quickly. With the availability of wider rims and disc brakes, road riders were exploring unpaved fire roads and gravel rural lanes in increasing numbers. They were taking part in a new breed of races and cycling events like Land Run 100 and Dirty Kanza that harken back to the extreme endurance tests of the early Tour de France. Former pro and Zipp ambassador Ted King won Dirty Kanza in 2018 aboard Zipp 303 Firecrest Tubeless Carbon Clinchers.


Ted King, a former road pro, now is a pioneer in gravel racing. He won the 2018 Dirty Kanza in Kansas aboard the Zipp 303 Firecrest Tubeless Carbon Clinchers. Photo by Wil Matthews

Ideal for ‘Spirited Riding’

The introduction of new technologies like tubeless and the 303 Firecrest 650b provided even greater options for “off road” roadies. In short, the versatility of the 303 combined with the widening definition of road riding have made the 303 an increasingly popular choice for a wide array of Zipp customers, from hard-core road racers and triathletes to newer riders looking for off-road adventure.

“People look to the 303 for its lighter weight and easier handling, especially for climbing and what I’ll describe as ‘spirited riding,’ said Alana Stewart, Consumer Specialist for the Zipp brand. “The perception is that 404 is too heavy for climbing and can be challenging in crosswinds, and while the 202 offers an aero benefit it’s less than the 303. In addition, the 303 is well suited for heavier riders.”

As she recently told one customer seeking advice on wheel choice, “the 303 is a fast-handling wheel great for all course conditions.”

That versatility, first proven in the Spring Classics, is the 303’s enduring appeal as part of road cycling’s future.

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